Yadu is one of the five Indo-Aryan tribes (panchajana, panchakrishtya or panchamanusha) mentioned in the Rig Veda (I.54.6, I.108.7, X.62.10).
The Hindu epic Mahabharata, the Harivamsha and the Puranas mention Yadu as the eldest son of king Yayati and his queen Devayani. The prince of King Yayati, Yadu was a self-respecting and a very established ruler. According to the Vishnu Purana, the Bhagavata Purana and the Garuda Purana,
Yadu had four sons, while according to the rest of the Puranas he had
five sons. The names of his sons are: Sahasrajit (or Sahasrada), Kroshtu
(or Kroshta), Nila, Antika and Laghu. The kings between Budha and Yayati were known as Somavanshi. According to a narrative found in the Mahabharata, and the Vishnu Purana,
Yadu refused to exchange his years of youth with his father Yayati. So
he was cursed by Yayati that none of Yadu's progeny shall possess the
dominion under his father's command. Thereby, he could not have carried
on the same dynasty, called Somavamshi. Notably, the only remaining
dynasty of King Puru was entitled to be known as Somavamshi. Thereby
King Yadu ordered that the future generations of his would be known as Yadavas and the dynasty would be known as Yaduvanshi. The generations of Yadu had an unprecedented growth and got divided into two branches.